1. Field of the Invention
The present invention relates to a punching unit for punching apparatus and, more particularly, to improvements in a structure around a die used in a punching unit set in the punching apparatus for producing holes in predetermined points of thin sheet materials, such as wiring base boards, flexible films, metal films, prepregs, or the like, and constituted mainly of a die and a die facing thereto.
2. Description of Background and Relevant Information
A punching unit for punching apparatus has previously been proposed by the applicant of the present invention in Japanese Patent Application No. Sho 62-102198.
The punching unit for punching apparatus according to the applicant's previous proposition comprises a support section formed in a nearly ]-shape or vertically oriented channel shape; a punch removably mounted on the upper half side thereof, such that it will face a die mounted on the lower half side of the support section; and a lifting mechanism for vertically moving the punch movably mounted on the support section, and removably connected to the punch.
According to the present applicant's previous proposition, the punching unit for punching apparatus has such an advantage that the punch can readily be replaced because of its releasability from the support section and the lifting mechanism.
The punching unit for the punching apparatus previously proposed by the present applicant has a problem to be solved that the punching unit is not fully applicable to accurately punching relatively large holes without distortion and burrs because it produces holes by as if pressing to cut a material.
The present invention has been accomplished in an attempt to solve the problem mentioned above, and has as its object the provision of a punching unit for punching apparatus that enables easy replacement of the punch and also thorough application to the punching of relatively large square holes.
To accomplish the aforementioned object, the punching unit for punching apparatus includes a punch removably mounted on the upper half side of a support section formed in a nearly ]-shape such that the punch will face a die mounted on the lower half side of the support section, and a lifting mechanism removably connected to the punch and vertically movably mounted on the support section to move the punch up and down; a means comprising a flat force-cutting blade is attached on the bottom end of the punch, a punch is rotatably mounted on the support section, and a rotating mechanism is provided on the support section for turning the punch through 90 degrees.
The means described above, using the structure that enables the mounting of the punch to, and the removal of the same from, the support section and the lifting mechanism, can fulfill the object to maintain the advantage of the present applicant's proposition, that is, the facilitation of punch replacement.
Furthermore, since the punch having a flat force-cutting blade is turned through 90 degrees by a punch rotating mechanism to cut each side of a square hole in the material, it is possible to accurately produce relatively large square holes without distortion and burrs, thus accomplishing the object of the present invention.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment when read in connection with the accompanying drawings.